Amar is a fun loving active 34-year-old who lives in Surat. He used to wear glasses which were interfering with his new-found love for Scuba Diving. He finally got his FemtoLasik done and was very pleased with his initial results. He had some night vision issues like halos around bright lights and glare from the oncoming headlights. His eye surgeon re-assured him that these will reduce after 6-12 months. He noticed minor improvements in his night vision problems but was still getting troubled especially during long drives at night.
He finally presented for a second opinion to the Centre for Lasik surgery at Advanced Eye Institute and Hospital. We examined him in detail and conducted a few tests like corneal topography, corneal aberrometry, muscle balance tests, pupil size, dry eye tests etc. His Lasik surgery was done properly and there was no issue with the surgery or the after-surgery recovery.
There were 2 small problems which were causing the night vision symptoms in his eyes.
First, his pupil diameter in dim light conditions was 7.5mm which was much larger than the zone of treatment which was 6.2mm. Secondly, he had an Intermittent divergent squint which was probably also affecting his night driving.
Initially we prescribed prismatic glasses with an anti-glare and anti-reflective coating to be worn at night. We also discussed with him the option of zone enlargement in case he does not benefit from just the prismatic glass trial. He was quite happy with the outcome after using prismatic glasses at night and didn’t opt for any further corneal laser surgery for zone enlargement. He did undergo squint surgery later to avoid wearing prismatic glasses at night.
Night vision issues after Lasik are very common and can range from minor glare, to haloes to severe starburst effects around light. People may experience minimal discomfort or may get highly troubled by the night vision issues. There are several reasons for night vision issues after Lasik.
- Large Pupil– Pupil is the aperture which allows light to enter the eye. The size of pupil varies from person to person and with age and with surrounding light conditions. Pupil tends to be larger in dim light conditions. It is mandatory to know the pupil size of an individual who wants to get Lasik done for glass removal especially in dim light conditions. In Lasik surgery, corneal curvature is altered in a specific zone with a certain diameter. Lasik surgeon tries to ensure that the zone of treatment is centered and covers the diameter of pupil (as measured in dim light conditions). However, in some cases this is not possible especially when the pupil diameter is very large and the size of refractive error and corneal thickness does not permit the zone of treatment to be so large. The larger the zone of treatment, thinner the cornea becomes after the procedure. So, in these cases sometimes it may be worthwhile to not plan a Lasik surgery. Lot of individuals have persisting night vision issues due to this mismatch between the zone of treatment and the size of pupil at night. If corneal thickness permits then topography guided zone enlargement can be performed for those people. People with minor night vision issues can just wear night glasses with anti-reflective coating.
- Minor residual refractive error– Some people can have minor residual eye power including myopia, hyperopia or astigmatism. Refractive error may be caused by an over or under-response of your cornea to the Lasik surgery. Those with minor residual power are often comfortable during the day but may experience night vision issues like halo. It is better to first use a correction glass at night and understand if this solves the issue and then plan for a re-treatment.
- Decentered lasik laser treatment– This happens when the zone of treatment is not centered during the procedure. It is a very rare thing to happen especially with the new generation laser machines which have an eye tacker and gives an indication about the decentration. In case decentered ablation is the cause for night vision issues it can be easily ascertained by corneal topography. In those cases where it is significant, a topography guided re-treatment can be done.
- Corneal flap problems– Another uncommon cause for night vision problem after Lasik is the flap related issue. Sometimes the corneal flap does not adhere correctly after it is replaced back on the cornea. If there are any folds or striae then these can be addressed and removed by a minor repeat procedure where flap is lifted again and repositioned.
- Dry eyes- Dry eye is a very common problem affecting the young generation. Too many hours are spent with the digital devices. This not only causes fatigue but also eye dryness. Sometimes the tear film instability due to dry eye can be significant. This in turn may cause some night vision issues. This also can be diagnosed and treated easily.
- Other minor issues– sometimes increased corneal aberrations or muscle imbalances like muscle insufficiencies, intermittent squint etc may also cause symptoms which increases during dim light conditions.
Overall a small group is more prone to develop night vision issues after Lasik. People with higher glass power and those with larger pupil are predisposed to have at least some night vision issues even after a very well performed Lasik. In such cases, it is worthwhile to re-consider the decision to do Lasik and opt for other options like glasses or contact lenses. Anyway, most of the time night vision issues reduce with time due to neuroadaptation. So, in some cases all we need is patience!
About Centre for Lasik Surgery at Advanced Eye Hospital and Institute at Sanpada, Navi Mumbai: Centre for Lasik Surgery at Advanced Eye Hospital and Institute is a state of art center for all those who want to get freedom from glasses. It is one of the most advanced centers for glass removal in western India.
All different procedures like Lasik, Femto Lasik, PRK, EpiLasik, ReLEx Smile Lasik, LasikXtra and ICL implantation are available under one roof. It has become very popular and trusted center for the residents of Vashi, Sanpada, Nerul, CBD Belapur, Kharghar, Panvel, Koparkhairane, Chembur and other parts of Navi Mumbai and Mumbai.
About Dr. Vandana Jain: Dr. Vandana Jain is an expert Cornea and Lasik surgeon. She has vast experience of performing laser vision correction procedures over a decade. She is well versed with all the latest techniques and advancements in laser vision correction procedures like LASIK, Femto Lasik, Smile Lasik, PRK, etc.
Dr. Jain ensures that all the patients undergo a detailed pre Lasik evaluation and then the best procedure and the technique is chosen for the patient to get satisfying results and to ensure long term safety.
Advanced Eye Hospital And Institute (AEHI) can be reached at (O): +91 22 67313636, (Emergency): +91 9167360360 or even through Email: firstname.lastname@example.org
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