SRIVENKATESWARA NETHRALAYA          

                                                               *** Advanced Eye care Hospital*****

Website: www.srivenkateshwaranethralaya.com

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Sri Venkateshwara Nethralaya, Eye Hospital & Lasik Centre has started its 3rd centre at Kengeri, Opp VidhyaGanapathy temple, old outer ring road, kengeri Satellite town. For Appointments @ our kengeri centre please call on 28487484, 28488484, 9148316772.. For Appointments @ RRnagar Pls call 28603343,28601143,28607713,9379512374, 9108539710.. For Appointments @ Ramanagara Pls Call 27274773, 27274776, 7019412265, 6361231756. Due To COVID-19, (1)  Appointment Scheduling over Phone  is a must, (2) Please follow the One Patient One Attender Policy strictly to avoid overcrowding  (3) Please Scrub with Alcohol based Sanitizer prior to entry  (4) There will be no entry without face masks for both attender and patient  (5) Please bear with us for enhanced waiting times between 45 minutes to 1.5 hrs before you can see the doctor (6) Please maintain social distancing of about 6ft at all times (7)  Please use digital modes of payment as much as possible and avoid cash transactions  (8) If you have fever, cough, breathing difficulty, or if you have a history of recent travel to another district or if you have been in contact with a COVID positive case, please do not visit the eye hospital at this time as you will be denied entry to the hospital, you have to visit the fever clinic in a covid first responder hospital and certified by them on your corona status before we are allowed to see you. (9) Avoid spitting in public places and avoid visiting overcrowded places for your own safety. Kindly cooperate

 

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?When Will I ever see sharp and clear without Glasses ??

     ?Can I ever get rid of these thick and heavy Spectacles by choice and discover natural eyesight?? 

 

  ?Have times not changed- why do i still need Glasses to see          clearly??

            ?Can i walk in with my old glasses and walk out with sharp and clear vision ??

                  ?Will finally people start to listen to what i have to say rather than always focus on the thick glasses which i am forced to wear??

                        ?Can i make the rest of my life - the best of my life ... and achieve spectacle free natural complete eyesight in a totally painless and safe manner using advanced technology within a matter of minutes??

Answer:   YES, Your Prayers could be answered instantly. Besides helping you  discover beautiful , Natural Eyesight & joining 25 million happy Lasik patients worldwide.. We will also help you donate your Glasses to the Poor.

Call Us on our Lasik Phone 91-80-28603343, 91-80-28601143, 91-28607713, 919379512374 or mail us at svneye@gmail.com

 

                                             

FAQ’s (Frequently Asked Questions) on Lasik Laser Treatment ..

1.Your practice/hospital is very far away in RR nagar, Bangalore, INDIA. Can you suggest to me anything near.

For most people, Painless, permanent Vision Correction by Lasik is a once in a lifetime procedure and so want to make the best choice for their eyes with zero compromises. So, If  you are seriously thinking of getting it done, distance should not matter and should be the last on your list of worries...However what does matter is the degree of care, and level of expertise that you seek. Most people desire the best for themselves and so catching that flight and travelling to Bangalore in a few hours or any other place for a once in a lifetime experience should not matter...Most of us love doing such things all the time and  If you love your eyes and your eyesight as much as we love restoring your eyesight to its normal state & seeing our trusting patients smile happily after each and every succesful Lasik, then you should meet us, we will guide you like none other in your every step towards achieving your goal.

Call Us on our Lasik Phone 91-80-28603343, 91-80-28601143, 919379512374 or mail us at svneye@gmail.com

2.From how long are you doing Lasik in your centre

We are in practice at Sri Venkateshwara Nethralaya, Raja Rajeshwarinagar, Bangalore from 2004 and We are the only centre in South West Bangalore to operate with a fully owned Lasik Laser Machine at a cost of 500,000 USD We are also the only centre to offer all forms of Vision correction starting from in house Lasik laser, Refractive IOL implantation , ICL,etc to our patients.

3. I know that most centres have more than 95% successful Lasik patients, but does your centre have unsuccesful patients who have gone to the courts to claim compensation for a bad result or in other words, do you have any pending cases or cases where you have paid compensation for a unhappy Lasik Patient

Fortunately in our practice since we perform the entire array of refractive correction procedures starting from Lasik to ICL to Refractive Lens Exchange, we are able to preoperatively determine the small group of people who are not likely to benefit from Lasik and offer them other procedures where a better result is expected. Cases where the mesopic pupils are large, Corneal thickness is low, Astigmatism is more than 4 D, Spherical power is more than -10 to -12D, Inferior steepening on topography, etc are the cases where case specific alternatives are suggested which have yielded good results in our practice.             

    And, No.. We have not had even a single case/complaint registered against our services whether it is lasik, or any other ophthalmic surgery till date. The main reason for our success is that we value the trust that our patients put in us  preoperatively and so, aim to overdeliver on the postoperative result to the best that technology permits in any given patient .

    Most Centres analyse data related to the spectacle power and the corneal thickness only, while advanced data related to higher order abberations is usually not acquired or discussed with the patient even if acquired, as it involves a deeper understanding of the subject.  At our centre, we not only perform an accurate refraction to determine you spectacle power, a detailed analysis of each patient's Higher order abberations is made with reference to their

Q values (peripheral corneal contour or shape) Normal cornea is prolate, Post myopic LVC it becomes spherical (for small corrections) & oblate for larger myopic corrections. But in Hyperopia it becomes Hyperprolate

Zernicke Polynomials (mathematical expression of the different components of corneal abberations),

RMS values (RMS is the square root of the average squared difference between the observed corneal tangential curve measurements at various points and their expected values, as estimated from the curve that best fits the actual corneal data),

Angular Frequency (No of times the error is repeated at the pupillary plane),

Directional Magnitude ( Towards the retina is + and away from the retina is - ),

Radial Order ( Method of classification in which any  corneal abberation above the 3rd order has complex coefficients that cannot be corrected by glasses or contact lenses)

Topographic patterns (based on the change in curvature pattern across the cornea to detect irregular astigmatism, and other progressive eye conditions like Keratoconus and PMD),

Corneal Thickness ( to diagnose keratoconus as well as calculate treatment depth),

Ablation profiles (Prolate vs non prolate ablation with Aspheric Transition zones) etc.

     Any abnormality in any of the parameters requires corresponding adjustments in the treatment profiles to ensure predictable and reproducible results. For Ex- Some patients may have abnormal Q values (Corneal contours) but low wavefront errors, In these cases we identify the wavefront errors using Zernicke polynomials to see if the absolute RMS values cancel out each other, then in these cases we advise  Optimised lasik or OATz which maintains the Pre op Q values and yields superior results by generating more laser pulses to the periphery leading to a larger Optic Zone. If Q values are exceedingly high with pre op Quality of Vision issues and subnormal vision, we advise Topo Lasik or CATz that generates a BFS for the abnormal corneal topography and the deviation from this BFS is analysed to create a unique treatment profile which also compensates for induced HOA as well as final refracion and if WF errors are exceedingly high >0.3micron RMS value at the 6mm zone with quality of vision issues, we advise a Full Wavefront Customised Lasik or  OPD-CATz. Some patients will require a combination of procedures  executed skillfully such as Intrastromal Keratotomy, Retinal Green Laser etc to ensure optimal results.  We constantly endeavour to acheive our targetted results as per the international peer reviewed studies and deliver accurate information to our patients. The background theoretical knowledge of the treating surgeon is vital to understanding every individual patients unique problems and providing acceptable, predictable & customized results in each and every case...

    These are the main reasons for our success rates (> 95%) at providing a painless, predictable and near permanent correction of refractive errors without risking suboptimal outcomes in any of our patients. Even in the remaining 4-5% of patients who have undercorrection, overcorrection or regression, future lasik enhancements may be considered to derive an acceptable result as the safety margin is higher on the highly efficient NIDEK platform as compared to other platforms as the Final Fit algorithm utilizes only 12microns per diopter of correction as compared to other platforms which utilize 20 microns per diopter of correction.

1D of correction with 5 mm optic zone, the depth is 8.33microns, for 6 mm OZ the depth is 12microns and for 7mm OZ it is 16.33 microns and for 8 mm OZ it is 21.33 microns

Even in the very rare case where a small  amount of spectacle power remains even after full permitted correction, the dependence on spectacles is vastly reduced and spectacle usage may be limited to only fine work. NIDEK is the only company to have received US FDA approval for its Excimer laser for OATz, CATz & OPD CATz Wavefront Lasik treatment (Final Fit TM Software).

                 

Besides Wavefront Abberometry, There are other parameters that needs to be evaluated prior to Laser Vision Correction, like Pentacam Analysis, Dry Eye Scan along with Scleral and Corneal Rigidity each using its own devices.

1. What Each Device Is & How It Works

         

   📌OPD-Scan (Wavefront Aberrometer + Topographer)

  • Full Name: Optical Path Difference Scan

  • Combines autorefractometry, keratometry, aberrometry, and corneal topography in one unit.

  • Principle: Measures how light waves are distorted as they pass through the eye → calculates refractive error and optical aberrations.

  • Provides:

    • Wavefront maps (higher-order aberrations)

    • Corneal topography (anterior surface curvature)

    • Refraction

    • Pupil size/centers

  • Useful for functional optics (how the whole optical system performs).

 

📌Pentacam (Scheimpflug Tomographer)

  • Uses a rotating Scheimpflug camera to image the anterior segment in 3D.

  • Measures:

    • Anterior & posterior corneal surfaces

    • Corneal thickness (pachymetry) map

    • Anterior chamber depth & volume

    • Lens density

    • Corneal elevation maps

  • It’s tomography, not just topography — includes posterior corneal surface.

KEY DIFFERENCES

Feature OPD-Scan Pentacam
Surface measured Anterior cornea + global optics Anterior + posterior cornea + full anterior segment
Optical quality Wavefront aberrations Does not measure wavefront
Pachymetry (thickness) No Yes (accurate pachymetry map)
Elevation maps Limited Yes
Anterior chamber angle & volume Limited Yes
Refractive diagnostics Strong Supportive
Uses Refraction, aberration analysis, topography Tomography, ectasia screening, cataract planning
Corneal tomography No Yes

2. When Each Is Better — Clinical Scenarios

✅ OPD-Scan is better for:

  • Refractive evaluation — assessing total optical system aberrations (especially higher-order aberrations).

  • Wavefront-guided LASIK/PRK planning.

  • Cases where functional optics (image quality) matter most.

  • Screening for subtle irregular astigmatism that affects vision quality rather than structure.

Bottom line: OPD-Scan tells you how well the eye functions optically.

✅ Pentacam is better for:

  • Corneal tomography — especially keratoconus screening and suspect ectatic disease.

  • Pre-refractive surgery screening — detecting early posterior corneal changes.

  • Cataract & IOL planning — anterior chamber depth, lens density.

  • Pachymetry maps — critical for glaucoma risk evaluation and corneal pathologies.

  • Post-cross-linking and corneal disease monitoring.

Bottom line: Pentacam tells you detailed 3D structure of the anterior segment, critical for safety and surgical planning.

🧠 Core Concept: Topography vs Tomography

  • Topography (like basic OPD maps) → curvature of anterior surface only.

  • Tomography (Pentacam) → true 3D reconstruction, includes posterior cornea and thickness distribution.

For detecting early ectasia, topography alone may miss posterior changes — that’s why tomography is superior.

🩺 Example Clinical Decisions

🟡 Case: Suspect Keratoconus

  • Pentacam is essential — can detect subtle posterior elevation changes and pachymetric thinning.

🟡 Case: Pre-LASIK Functional Optics

  • OPD-Scan helps quantify higher-order aberrations and plan ablation profiles.

🟡 Case: Routine Cataract Workup

  • Pentacam gives anterior chamber depth, lens density, and corneal thickness → useful for IOL calculators.

📌 So Which Is “Better”?

There is no universal answer — it depends on what question you’re trying to answer.

  • 👉 Pentacam is generally better for structural assessment and screening (especially ectasia/cataract planning).

  • 👉 OPD-Scan is better for understanding optical performance and wavefront aberrations.

In modern clinical practice, many surgeons use both:

  • Pentacam for safety & structural evaluation.

  • OPD-Scan for optical quality and aberration-based refractive planning.

🧠 A Good Rule of Thumb

Pentacam = Anatomy & Safety
OPD-Scan = Optical Performance & Function


 Pre-op work-up: what each machine actually contributes

🔹 OPD-Scan

→ answers: “How good is the optical quality of vision?”

🔹 Pentacam

→ answers:

“Is the anatomy safe and suitable for surgery in LASIK?

"Is the Anterior segment Volume good enough to accmodate a ICL?”

" What is the Corneal Thickness, curvature, and AC depth so that i can get the most accurate  IOL  power?

" What is the Corneal Abberation Vs Lenticular Abberation  Vs  Total Higher order Abberation that will determine my choice of the Premium Abberation correcting Intra Ocular Lenses?

 " Does the WF abberometry, PSF  and MTF  explain the visual dissatisfaction in patients with mild to moderate cataract and reading well on the  Snellen Chart and hence justifies cataract surgery/Refractive Surgery?

All these Investigations are complementary, not mutually exclusive or redundant..

🟢 CATARACT PRE-OP

✔ OPD-Scan in cataract

 OPD-Scan helps with functional optics:

  • PSF (Point Spread Function)
    → tells quality of retinal image degradation

  • MTF (often paired conceptually)
    → contrast transfer at different spatial frequencies

  • Corneal vs internal aberrations

    • Separates corneal HOAs from lenticular/internal HOAs

  • Helps in:

    • Deciding premium IOL candidacy

    • Explaining poor quality vision despite mild cataract

    • Counselling expectations

📌 Teaching pearl:

Cataract is not just opacity — it’s also aberration induction by the lens.

✔ Pentacam in cataract

  • Corneal curvature (K values)
    → IOL power calculation

  • Total corneal power (esp. posterior cornea contribution)

  • Anterior chamber depth & volume

    • Important for:

      • Phakic IOL exclusion

      • Shallow AC risk

  • Pachymetry

    • Surgical safety

    • Glaucoma co-evaluation

  • Lens densitometry

    • Objective cataract grading

  • Astigmatism analysis

    • Planning toric IOLs

📌 Exam line:

Pentacam is critical for biometry accuracy and anatomical safety in cataract surgery.

 LASIK / REFRACTIVE SURGERY PRE-OP

✔ OPD-Scan in LASIK

  • Wavefront (WF) data

    • Total ocular aberrations

    • Corneal vs internal split

  • Higher-order aberrations

    • Coma, spherical aberration

  • Wavefront-guided / wavefront-optimized planning

  • Pupil dynamics

    • Scotopic pupil size → night vision risk

📌 Key concept:

OPD-Scan decides how customized the ablation should be.

✔ Pentacam in LASIK

This is non-negotiable for safety —

  • FFKC (Forme Fruste Keratoconus)

  • Posterior corneal elevation

    • Earliest ectatic change

  • Pachymetric progression index

  • Thinnest point location

  • Belin–Ambrosio Display (BAD-D)

📌 Golden rule:

A normal anterior topography does NOT rule out keratoconus — posterior cornea decides.

Put it together (one-line answer)

In cataract surgery, OPD-Scan evaluates optical quality and aberrations, while Pentacam provides corneal curvature, pachymetry, anterior chamber parameters and IOL planning data.

In LASIK, OPD-Scan guides wavefront-based ablation, and Pentacam is essential to exclude ectasia by detecting FFKC and posterior corneal abnormalities.

🔑 Ultra-high-yield summary (remember this)

  • OPD-Scan = FUNCTION

  • Pentacam = STRUCTURE + SAFETY

  • LASIK without Pentacam = medico-legal risk

  • Premium IOL without OPD-Scan = patient dissatisfaction risk

  • Some clinicians use Scissoring reflex on Retinoscopy to rule out Posterior Keratoconus when the OPD maps are normal.

Scissoring reflex can appear very early in posterior corneal ectasia (“posterior catacombs”), sometimes when:

  • Anterior corneal curvature is still normal

  • Placido-based topography is normal

  • Only posterior elevation / pachymetric asymmetry is abnormal on Pentacam

In other words:

Scissoring reflex can be an early functional sign of posterior corneal irregularity.

🧠 Why this happens (conceptual explanation)

What causes a scissoring reflex?

Scissoring on retinoscopy occurs due to:

  • Irregular astigmatism

  • Non-uniform refractive power across the pupil

This does not require anterior surface distortion alone.

Posterior cornea contribution

  • The posterior corneal surface contributes ~−6 D of refractive power

  • Small irregularities posteriorly can:

    • Distort wavefronts

    • Create optical asymmetry

    • Produce scissoring before visible anterior steepening

So even when:

  • Anterior K values look normal

  • Placido rings look symmetric

➡️ Retinoscopy may already show scissoring


In true posterior keratoconus / early ectasia, Pentacam will detect changes earlier and more reliably than a scissoring reflex.


🔍 Why Pentacam detects earlier than scissoring

1️⃣ What Pentacam detects (structural)

Pentacam detects micron-level structural changes, including:

  • Posterior corneal elevation

  • Pachymetric thinning and asymmetry

  • Abnormal thickness progression

  • Belin–Ambrosio deviation (BAD-D)

These appear before optical irregularity becomes clinically appreciable.

2️⃣ What scissoring reflex represents (functional)

Scissoring is a functional optical sign, caused by:

  • Irregular astigmatism

  • Non-uniform refractive power across the pupil

For scissoring to appear, posterior irregularity must be:

  • Large enough

  • Optically asymmetric

  • Aligned with the pupillary axis

👉 Very early posterior changes may not yet distort the wavefront sufficiently to cause scissoring.


Stage Pentacam Retinoscopy
Ultra-early posterior ectasia Abnormal (posterior elevation, BAD-D) Normal
Early FFKC Abnormal ± unstable reflex
Subclinical KC Abnormal Scissoring appears
Clinical KC Grossly abnormal Obvious scissoring


Therefore:

Pentacam abnormalities precede scissoring reflex which usually precede Anterior curvature abnormalities.

🔍 Pentacam parameters to assess before LASIK

(Think: Shape → Thickness → Posterior surface → Risk indices)

Device reference

Pentacam

🟥 1️, Belin–Ambrosio Enhanced Ectasia Display (BAD-D)

MOST IMPORTANT

What to look at

  • Final BAD-D value

  • Individual components:

    • Df (front elevation)

    • Db (back elevation)

    • Dp (pachymetry)

    • Dt (thinnest point)

    • Da (progression)

Cut-offs (high yield)

  • < 1.6 → Normal

  • 1.6 – 2.6 → Suspect (relative contraindication)

  • > 2.6 → Ectasia risk → LASIK contraindicated

📌 Rule:

If BAD-D is abnormal → stop. Don’t negotiate.

🟥 2️ Posterior corneal elevation (critical)

Earliest ectasia change

Check:

  • Posterior elevation map

  • Elevation at thinnest point (BFS float)

Cut-offs:

  • ≤ +12 µm → acceptable

  • > +15 µm → suspicious

  • > +20 µm → no LASIK

📌 Posterior abnormality alone is enough to reject LASIK, even if front surface is normal.

🟥 3️ Pachymetry map & progression

Thickness matters more than absolute CCT

Evaluate:

  • Thinnest pachymetry (not central)

  • Location of thinnest point

  • Pachymetric progression index (PPI)

  • Ambrosio relational thickness (ART)

Cut-offs:

  • Thinnest point: ≥ 500 µm (preferred)

  • ART:

    • > 340 µm → safe

    • < 300 µm → high ectasia risk

📌 Inferior displacement of thinnest point = red flag


What is PPI (Pachymetric Progression Index)?




📌 Definition

PPI describes how corneal thickness increases from the thinnest point toward the periphery.

In a normal cornea:

  • Thickness increases gradually and symmetrically

In ectasia:

  • Thickness increases rapidly and irregularly

🧠 Think of it like this

Imagine walking uphill from a valley:

  • Normal cornea → gentle slope

  • Keratoconus / ectasia → steep cliff

PPI quantifies how steep that “thickness slope” is.

📊 Types of PPI (you’ll see these on Pentacam)

  • PPImin

  • PPIavg

  • PPImax ← most important

🚦 Interpretation (high-yield)

  • Normal: PPImax ≈ < 1.2–1.3

  • Suspicious: ~1.3–1.6

  • Abnormal (ectasia risk): > 1.6

📌 Key idea:

A cornea can be thick centrally but still unsafe if thickness progression is abnormal.


🔹 What is ART (Ambrosio Relational Thickness)?


📌 Definition

ART combines corneal thickness with pachymetric progression.

Formula (conceptual):

ART = Thinnest corneal thickness ÷ PPI

So ART answers:

“Is this cornea thick enough relative to how fast it thins?”

🧠 Why ART is powerful

  • CCT alone can be misleading

  • ART tells you functional thickness safety

Example:

  • Cornea A: 520 µm, smooth progression → safe

  • Cornea B: 520 µm, steep progression → unsafe

ART will be low in Cornea B.

🚦 ART cut-offs (VERY IMPORTANT)

  • ART > 340 µm → Normal / safe

  • ART 300–340 µm → Borderline

  • ART < 300 µm → High ectasia risk → reject LASIK

📌 ART is one of the strongest predictors of post-LASIK ectasia.

🔗 Relationship between PPI and ART (remember this)

  • High PPI → thickness changes too fast ❌

  • Low ART → cornea structurally unsafe ❌

They are two sides of the same coin.

🧠 One-line exam / viva answers

PPI:

Pachymetric Progression Index measures the rate of increase in corneal thickness from the thinnest point to the periphery.

ART:

Ambrosio Relational Thickness is the ratio of thinnest corneal thickness to pachymetric progression and reflects biomechanical safety of the cornea.

🔑 LASIK decision rule (clinic-ready)

  • High PPI + Low ART = NO LASIK

  • Even if:

    • K values are normal

    • Anterior topography looks fine

    • Vision is good


🟥 4️ Anterior corneal surface (still important)

(Not sufficient alone, but still assessed)

Look at:

  • Axial & tangential maps

  • Inferior–superior (I–S) asymmetry

  • Skewed radial axes

Red flags:

  • Inferior steepening

  • Asymmetric bow-tie

  • Irregular astigmatism

📌 Normal anterior topo does NOT clear LASIK if posterior surface is abnormal.

🟥 5️ K values (supportive, not decisive)

Typical safe range:

  • Kmax < 47 D

  • Kmean ~ 43–44 D

Concern:

  • Kmax > 47.5 D → ectasia risk increases

📌 K values alone should never be used to approve LASIK.

🟥 6️ Corneal thickness vs ablation safety

(Not Pentacam alone, but derived)

You must ensure:

  • Residual stromal bed (RSB) ≥ 250–300 µm

  • Percent tissue altered (PTA) < 40%

📌 Pentacam gives you true pachymetry distribution, essential for this calculation.

🟡 7️ Anterior chamber depth (secondary)

More relevant for:

  • Phakic IOL consideration

  • Safety profiling

Not a LASIK rejection criterion by itself.

🧠 LASIK clearance logic (mental flowchart)

BAD-D normal?
→ Posterior elevation normal?
→ Pachymetric progression normal?
→ Adequate thickness & RSB?
→ THEN consider OPD-Scan & refractive planning

If any one of the first three fails → NO LASIK

🧾 One-liner

Before LASIK, Pentacam evaluation must focus on BAD-D, posterior corneal elevation, pachymetric progression and thinnest point location; anterior topography and K values are supportive but insufficient for ectasia risk assessment.


🔑 Final clinical pearl

  • Pentacam decides SAFETY

  • OPD-Scan decides QUALITY

  • Never let wavefront or Pentacam alone “tempt” you into operating on an unsafe cornea. 


So what are these parameters?

🟥 1️ Belin–Ambrosio Display (BAD-D)

PRIMARY LASIK GATEKEEPER 
“Image source: EyeGuru.org (link)”

🟢 NORMAL (LASIK OK)

  • BAD-D < 1.6

  • All bars green

  • No isolated red component

  • Symmetric pachymetry graph

🔴 ABNORMAL (REJECT LASIK)

  • BAD-D > 2.6

  • Red in Db (posterior) or Dp (pachymetry)

  • Even ONE red bar = stop

📌 Rule:

BAD-D abnormal → LASIK contraindicated, irrespective of everything else.


🟥 2️ Posterior Corneal Elevation

EARLIEST ECTASIA MARKER
“Image source: EyeGuru.org (link)”

“Image source: EyeGuru.org (link)”

🟢 NORMAL

  • Posterior elevation at thinnest point
    ≤ +12 µm

  • Symmetric, smooth elevation map

  • No focal hot spot

🔴 ABNORMAL (REJECT LASIK)

  • Elevation > +15–20 µm

  • Localized inferior or inferotemporal bulge

  • Posterior changes even if anterior map looks normal

📌 Golden rule:

Posterior abnormality ALONE is enough to reject LASIK.

🟥 3️ Pachymetry Map & Progression

THICKNESS DISTRIBUTION > CCT


“Image source: EyeGuru.org (link)”

“Image source: EyeGuru.org (link)”

NORMAL

  • Thinnest point central or para-central

  • Smooth concentric thinning

  • ART > 340 µm

  • PPI within normal range

🔴 ABNORMAL (REJECT LASIK)

  • Inferior displacement of thinnest point

  • Abrupt thickness drop

  • ART < 300 µm

  • Steep pachymetric progression curve

📌 Exam pearl:

A 520-µm cornea can still be unsafe if thickness progression is abnormal.

🟥 4️ Anterior Elevation Map

SUPPORTIVE BUT NOT DECISIVE

“Image source: EyeGuru.org (link)”

🟢 NORMAL

  • Elevation < +10–12 µm

  • Symmetric pattern

  • No focal hot spots

🔴 ABNORMAL

  • Localized anterior elevation

  • Inferior bulge

  • Asymmetry between eyes

📌 Teaching point:

Anterior map may be normal in early disease — don’t rely on it alone.

🟥 5️ Anterior Curvature (Axial/Tangential)

PLACIDO CAN MISS EARLY DISEASE 
“Image source: EyeGuru.org (link)”

“Image source: EyeGuru.org (link)”

🟢 NORMAL

  • Symmetric bow-tie

  • No inferior steepening

  • Regular astigmatism

🔴 ABNORMAL

  • Asymmetric bow-tie

  • Inferior steepening

  • Skewed radial axes

📌 Reality check:

Normal axial map ≠ safe LASIK.

🟥 6️ Kmax

SUPPORTIVE ONLY 
“Image source: EyeGuru.org (link)”

“Image source: EyeGuru.org (link)”

🟢 NORMAL

  • Kmax < 47 D

🔴 CONCERN

  • Kmax > 47.5 D

  • Rapid inter-eye asymmetry

📌 Never use Kmax alone to clear or reject LASIK.

🧠 FINAL LASIK REJECTION LOGIC

❌ BAD-D abnormal
❌ Posterior elevation abnormal
❌ Pachymetric progression abnormal

➡️ ANY ONE = NO LASIK

Even if:

  • Vision is 6/6

  • Refraction stable

  • OPD-Scan looks beautiful

  • Patient is begging

Pentacam rejection for LASIK is based primarily on Belin–Ambrosio deviation, posterior corneal elevation and pachymetric progression; anterior curvature and K values are supportive but insufficient for ectasia risk assessment.

Call Us on our Lasik Phone 91-80-28603343, 91-80-28601143, 919379512374 or mail us at svneye@gmail.com

4. Where did the treating doctor get trained from?

Our doctors are qualified from apex institutes such as All india Institute of Medical Sciences, AIIMS in New Delhi, India. AIIMS is the apex national institute for training postgraduates in all medical and surgical specialities.

In fact  Dr Saravana Kodandapani, MD was a teaching registrar at AIIMS.. training other doctors in subspeciality practice for advanced ophthalmic procedures for more than 5 years. He has over 16 years of experience in surgical and medical ophthalmology and has published papers in various international journals. To know more about Dr Saravana, Please click here.

Dr Sukanya is qualified from Rajaji Post Graduate Centre for Ophthalmology in Madurai, TN, India. Besides Cataract and Glaucoma, She has interests in Refractive Surgery, Contact Lenses and Lasers.  To know more about Dr Sukanya, Please click here.

5. What is the actual or real cost of Lasik Laser treatment ? Why is the Lasik Laser treatment so expensive ?

Well, To answer your question the Premix gas argon Fluoride costs around 40,000 rupees (600 USD approx) per fill and the consumables cost around 6000 rupees (110 USD approx). The overheads costs are approximately Rupees 1500 per patient (20 USD approx). Add to that Hospital Charges, Surgeon fees etc.Then there is the Equipment Cost- The Equipment costs around Rupees 2.75Crores (5,00,000 USD) and the AMC for the machine itself costs aroundRupees12 Lakhs per annum (24000 USD approx).. That is why in most of the developed world such as US,Japan and Europe, they charge around $1000 - $1500 for Each Eye especially for the Advanced state of the Art Wavefront Customised Lasik. You can read about it here. The above calculations are made at the rate of 1 USD= Rs 70. Now the USD/INR rate is much higher.   Recently, with the war in Ukraine choking the supply lines for neon, helium and Argon Fluoride gas to the rest of the world, the cost of these noble gases used in all the excimer lasers has risen exponentially to almost 10 times. You can read more about it here. However as we have a long term agreement with our global suppliers, we are still able to maintain a reasonable cost structure to our patients who stand to benefit even from our low prices even when other service providers all over the world have to raise their prices.

Call Us on our Lasik Phone 91-80-28603343, 91-80-28601143, 919379512374 or mail us at svneye@gmail.com

 6. OK, I have spectacle power(Short Sight, Long Sight, Astigmatism), What are my Laser Vision Correction (LVC) options?

We offer Laser Vision correction services in a price band of Rupees 30,000-85,000. This includes correction of Spherical and cylindrical power in the Basic Packages and correction of Higher order Abberations in the Advanced Packages.

BASIC PACKAGE

      Normal PRK-Rs 35,000/-

      Regular Lasik- Rs 35,000/-

ADVANCED PACKAGE

       Wavefront Optimised Lasik / PRK - Rs 1,00,000/-

       Wavefront Customised Lasik / PRK- Rs 1,25,000/-

       Topo Guided Lasik / PRK- Rs 1,55,000/-

Further reduction in the Basic Package is possible if your power is predominantly spherical with negligible cylindrical component. To know more click here)

Call Us on our Lasik Phone 91-80-28603343, 91-80-28601143, 919379512374 or mail us at svneye@gmail.com

PRK Educational Video                                                            

  

 Lasik Educational Video

     

 7. What is the difference?

Lasik is the latest technology and is totally painless as it corrects from inside out and that the patient is almost normal after a few minutes to the point of going home and can resume normal work the next day only, while PRK (PhotoRefractive Keratectomy) may cause a little discomfort for a few days as it treats from outside in, and may take a longer period for the vision to recover fully. However, by the end of one week, there is no difference between PRK and lasik. PRK is considered to be safer as compared to LASIK in terms of ectasia and absence of flap related issues.

    Also, the difference between Wavefront Optimised & Customized Treatments translates into differences in Night Vision--Glare, Haloes & Ghost images.  Optimised LVC provides the same quality of night vision as natural eyesight retaining a few imperfections of the normal human optical system,, while Customised LVC aims to achieve a ideal Optical system which translates into a much superior  overall quality of daytime / night vision. Regular Lasik/PRK provides the same quality of Vision as seen with Glasses.

Wavefront Optimised Lasik-                                                             

      

 Wavefront Custom Lasik

  

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          8. Can I wear glasses for the time being or may be even permanently as LVC does not sound financially viable to me?

Yes, You can continue to wear glasses for the rest of your life although the quality of vision would be nowhere as near as a well done Laser Vision correction procedure. Again remember that Spectacles have limitations that include but are not limited to the following

1.    it does not cure myopic disease process and

2.    Reduces the eye strain by only around 70-80%

3.    Requires the wearer to suffer compulsory lifelong handicap that may include legal blindness when spectacles are not worn even temporarily.

4.    Every Year as the Weakness Progresses, One has to change the Spectacles for a higher power.

 Laser correction will provide a possible permanent correction in a safe and effective manner along with superior night vision in a totally painless setting for a overwhelming majority of patients. Even in the small minority of patients who have undercorrection, overcorrection or regression etc, Additional Enhancements may be done to finetune the end result so that the maximum possible vision is achieved and is better than the original vision prior to lasik.

Having Natural Eyesight is different from artificially enhancing your vision with glasses. Normal Natural EyeSight helps you to be spontaneous in all your acitivities and you are always ready. Glasses retard that spontaineity in every action of yours and you tend to lag behind in your response time in comparison to normal people.

Call Us on our Lasik Phone 91-80-28603343, 91-80-28601143, 919379512374 or mail us at svneye@gmail.com

 

          9. My comment is that it is still way too expensive for people like me although I might be able to afford it in the future.

    Think about this: You never have to worry about your eyesight again for the rest of your life. This is a prime motivator for a lot of people. What is  God Given normal vision for others... With LASIK eye treatment, you can enhance your  own vision to even better than those normal people out there and  enjoy the world in true, bright and beautiful clarity—for your whole life—without slipping on specs or popping in contacts. If that is not a blessing, ask yourself  what else is ….? Lasik is amazing - to wake up and see the clock clear and sharp - can't beat it. Financial constraints are only relative and never ending... If you are serious about correcting your visual disability, Start Planning for your treatment right away. The material choices we make in life whether buying a mobile phone, or a vehicle or a laptop etc are based on our priorities. As Physicians, Our Job in motivating you is complete if you are able to prioritize correction of your visual disability or handicap first on your list of things to do  for yourself instead of splurging on expensive phones, jewellery, laptops or vehicles.

From Time immemorial , Sharp Vision was considered as  the most precious asset one can ever possess. More than 70% of the sensory input to the brain about the surroundings comes through our eyes and our day to day performance in everything we do depends heavily on Good, Natural & Sharp Eyesight.  There is an age old sanskrit saying "Sarvendriyanam nayanam pradhanam" ( OF ALL THE SENSES, EYES ARE THE MOST IMPORTANT ) As we prepare our patients further into the demanding technological requirements of the 21st century, acheiving sharp eyesight for our patients without any aids remains the foremost focus in terms of technology, expertise, Skill sets as well as financial viability.

    We do have tailor made financial solutions and Monthly Lasik Investment Programmes which are helpful for a lot of patients and enable them to undergo their treatments in just under a Year. If you have made up your mind to acheive natural eyesight, but have financial / logistic constraints...Come and talk to us, we will deliver the best possible result in your case in the best possible time.

If you have predominantly spherical error only and considering only the basic laser correction procedure, you may consider the following offer too which is economical for most patients and comes at a reasonable cost after concession / discount. We are able to give such honest pricing to our patients as we fully own our Laser Machine.

Others will never be able to match our pricing because most of the Lasik surgeons dont provide Laser vision correction in house, but usually have tie ups with company operated and owned centres where they themselves will have to pay a rental fee to the facility operator apart from a user fee to the leasing company that imports and leases the machine to the facility operator as well as royalty on a pay per usage basis to the original manufacturer of the machine for each eye. There is a mark up at every level and usually the mark ups are higher for patients who are referred by outside doctors / Lasik Surgeons as they then follow a model minimal investment and maximum returns approach with a linear risk spread for the high investment that this service requires . Ultimately the consumer or the patient is the person who has to bear the entire expenses  including the mark ups.

Again, If you have made up your mind to acheive natural eyesight, but have financial / logistic constraints...Come and talk to us, we will deliver the best possible result in your case in the best possible time at the best possible price.

This scheme was valid till June 30th, 2017. However, we have continued  this scheme even later as a large number of economically underpriviliged patients request us to do so. So, Be rest assured, you can now undergo your long awaited treatment at a cost which is most economical. To avail this offer, You can  call on the above numbers 91-80-28603343, 28601143, 9379512374,  and our receptionist will coordinate the appointment scheduling for you to undergo further investigations to determine your eligibility. Please do not engage the receptionist with your medical details &/or financial details. In case you wish to discuss your specific case in depth, you may mail us directly at svneye@gmail.com with your name, age, sex, address, phone no, and a brief introduction to your case along with the relevant medical reports. We will then get back to you with our advice. 

While we will reduce our fees substantially in making this affordable to a large segment of our underprivileged patients, we do not compromise on the overall outcomes and successful results due to this. Most Patients are afraid of becoming the product themselves when they are unable to pay for the product i,e  Underprivileged patients who pay less than the regular fees are afraid that they will undergo the procedure in the hands of trainees who have paid huge sums to the Lasik Centre to undergo training. This may happen in BIG hospitals / Chains where they take trainees in paid training programs and use camp patients as fodder to feed them compromising the results. If you wish to know more about such practices and why they occur, you may read about them here.

However, at our centre all patients are operated by Dr Saravana who is our chief Lasik surgeon and are operated on the same machine irrespective of their package status. The best possible results that can be achieved in each case is carefully discussed preoperatively and patients are guided into the procedure only after they are clear about what they can expect in terms of visual outcomes after the procedure.

Call Us on our Lasik Phone 91-80-28603343, 91-80-28601143, 919379512374 or mail us at svneye@gmail.com

        10. Can you tell me more about helping me with financial solutions / Laser Investment Programmes for undergoing Wavefront Optimised/Customised Laser vision correction which i understand is more expensive.

     Yes, If you are a Credit Card Holder (VISA/MasterCard), you can avail the complete treatment immediately (Easy EMI option) &  pay back in easy 3 / 6 Month EMI option without additional charges with a simple phone call to your credit card company.

    Also , In case you do not have access to credit card or bank credit or personal funds to finance the procedure right away, We do have the Following Monthly Investment programmes which will enable you to undergo the procedure within 6 - 12 months. In case you are unable to undergo the procedure for any reason, this offer comes with a Money Back Guarantee along with Interest if you wish to cancel your membership . There is however a cancellation fee and a minimum duration of payments to be eligible for refunds.  If you have financial constraints, the following tailor made plans enable  you as a patient to achieve financial viability for Laser Vision Correction with minimal risk on your investment

Joining Fees   NIL   NIL   NIL   NIL
Laser/Lasik Investment Plans(LIP)   Economy Plan   SuperSaver Plan   Freedom Plan   Premium Plan
-Total Duration   12months(1year)   6months   12months(1year)   6months
-Lasik Type   WF Optimised   WF Optimised   WF Customised   WF Customised
-DownPayment   NIL   Rs 20000/-only   NIL   Rs 25000/-only
-Monthly Payment   Rs 6000/-only   Rs 8000/-only   Rs 7000/-only   Rs 10000/-only
-Spectacle Frame + Optical Lens     (OR)  EW Contact Lens at the time of joining and payment of First Instalment    FREE    FREE    FREE    FREE
-Lasik  Pre Op Investigation Charges    FREE    FREE    FREE    FREE
-Lasik Treatment   After 1 year  After 6 months   After 1year  After 6 months
-Post Operative Medications    FREE     FREE    FREE    FREE
    Refunds        
-Refund on Cancellation   Yes (After 6 months)   Yes (After 3 months)   Yes (After 6 months)   Yes (After 3 months)
-Simple Interest accrued on the Deposit   6% per annum   6% per annum   6% per annum   6% per annum
-Cancellation Charges   Rs 3000/- only   Rs 3000/- only   Rs 3000/- only   Rs 3000/- only

  Refund options are available to all  patients who pay their instalments regularly on time but cannot undergo the procedure for personal reasons. The request can be made within a maximum period of 3 months after the last instalment is paid. The entire deposited amount  will be refunded along with simple interest after deducting the cancellation charges. Cancellation charges as specified will be applicable to cover the costs of preoperative investigations to determine eligibility to undergo LVC. However you can retain the  contact lenses or spectacles. No Refunds (partial/complete) are applicable after the procedure is performed.

    If you have purchased Spectacles from our optical outlet in the last 30 days, you can join any scheme in this programme and we will adjust the full purchase value of your optical product against your instalments (50% towards the first instalment and 50% towards the final instalment)

Call Us on our Lasik Phone 91-80-28603343, 91-80-28601143, 919379512374 or mail us at svneye@gmail.com

 11. I was previously told that I may  not be a suitable candidate for lasik due to thin cornea at other centres,-Is there any advancements in technology that will allow successful lasik for my eyes?

Majority of lasik centres in Bangalore use a variety of Excimer Laser platforms including  the  old Zyoptix platform from Bausch and lomb which uses around 20 microns of corneal thickness per diopter of correction. We use the Latest Nidek platform called EC-5000 CX11 which uses around 12 microns of corneal thickness per Diopter of correction.

1D of correction with 5 mm optic zone, the depth is 8.33microns, for 6 mm OZ the depth is 12microns and for 7mm OZ it is 16.33 microns and for 8 mm OZ it is 21.33 microns

 

 So for a given amount of Spectacle power, our machine utilizes less amount of tissue than other machines and so is able to correct larger errors easily which is not possible with other machines. You can read about it here and here. We also use the Moria keratome which raises a flap of 90-100 microns thick which is much less as compared to the Hansatome used elsewhere where the flap size is around 160 microns. This is comparable to the flap size achieved with Femtosecond Lasers and provides us the optimal flap configurations achieved with FS laser. So some patients who may have been refused lasik elsewhere due to insufficient corneal thickness  may find that they become eligible for laser vision correction on the Nidek platform and so approach us for treatment. As technology evolves we may be able to perform LVC even for those patients whom we too currently refuse for treatments. Even for patients considering to undergo Lasik  elsewhere in Zyoptix  /Alcon Wavelight / Zeiss platforms , you must enquire if your safety margin in Nidek Platform is higher as this Platform preserves a larger amount of corneal tissue for any given power among all the various available platforms. To know more about NIDEK Excimer Laser EC 5000 CXII, click here

                                     

 

                                             

If you are considering Laser Vision Correction and want to communicate with us, Don't just sit there, please send a mail to drsaravana@srivenkateshwaranethralaya.com. You could also become a member of a Patient Self Help Group that we have created on Facebook. This membership is free and contains access to our patients who have undergone Lasik and what they have to say about the procedure as well as our services. CliCK HERE for further details

?Remember - Sharp and Natural spectacle free Eyesight is now

                          only a click away.

    ?Your Life changes the way you choose to change.

          The choice is completely yours unless you want to leave it to chance.

        ?You can recover Spectacle free eye sight within minutes and gift 

                yourself  freedom from glasses.

            ?Value your Eye....Trust your Doctor....Adapt to Technology....

                 Be Blessed with what you desire.

                ?Discover sharp eye sight in the blink of an eye.....

 

A phone call from your door to ours could make the rest of your life

                                             the best of your life.

Call Us on our Lasik Phone 91-80-28603343, 91-80-28601143, 919379512374

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